1. Field of the Invention
The present invention relates to a shift lever locking device suitable for use with an automatic transmission, which is employed in a shift lever of the automatic transmission and restrains the shift lever from shifting so as to be locked at a specified shift position.
2. Description of the Related Art
A shift lever for an automatic transmission is constructed in such a manner that a detent pin attached to the shift lever is moved in the axial direction of the shift lever so as to be disconnected from a detent plate, thereby enabling the shift lever to be shifted to a desired shift position.
As a shift lever locking device capable of operating the shift lever only under specified conditions, e.g., only when a brake is pressed, there is known one in which a shift lock plate restrains a detent pin attached to a shift lever from shifting. In this type of shift lever locking device, when the shift lever is in a parking range (P range), the detent pin is brought into engagement with the shift lock plate and a plate stopper prevents the shift lock plate from movement, thereby preventing the shift lever from shifting. When, on the other hand, the brake is pressed, a solenoid is energized to move the plate stopper to a desired direction so as to enable the movement of the shift lock plate, thereby making it possible to shift the shift lever to a desired shift position.
Further, a shift lever locking device is also known in which only when the solenoid is electrically connected to an ignition-key inserting cylinder and the shift lever is at the parking range and when the ignition key is inserted into the ignition-key inserting cylinder and put in the ON position, the solenoid is energized to enable the movement of the detent pin, thereby making it possible to shift the shift lever to a desired shift position.
It is needless to say that the shift lever locking device for the automatic transmission is required to have high dimensional accuracy and assembly precision. However, this is not easily achieved since the shift lever locking device is comprised of a plurality of components. Therefore, measures for rectifying this situation have been demanded.